U.S. patent number 10,069,080 [Application Number 15/139,074] was granted by the patent office on 2018-09-04 for organic light emitting display device.
This patent grant is currently assigned to LG DISPLAY CO., LTD.. The grantee listed for this patent is LG DISPLAY CO., LTD.. Invention is credited to Dohan Kim, Jungkeun Kim, Jeongdae Seo.
United States Patent |
10,069,080 |
Kim , et al. |
September 4, 2018 |
Organic light emitting display device
Abstract
An organic light emitting display device is discussed. The
organic light emitting display device may include at least one
light emitting part between an anode and a cathode, the light
emitting part including at least one organic layer and a light
emitting layer, wherein the organic layer includes an organic
compound, and the organic compound includes a triazine compound
having a substituent with a steric effect.
Inventors: |
Kim; Dohan (Goyang-si,
KR), Kim; Jungkeun (Seoul, KR), Seo;
Jeongdae (Incheon, KR) |
Applicant: |
Name |
City |
State |
Country |
Type |
LG DISPLAY CO., LTD. |
Seoul |
N/A |
KR |
|
|
Assignee: |
LG DISPLAY CO., LTD. (Seoul,
KR)
|
Family
ID: |
55910162 |
Appl.
No.: |
15/139,074 |
Filed: |
April 26, 2016 |
Prior Publication Data
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Document
Identifier |
Publication Date |
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US 20170148995 A1 |
May 25, 2017 |
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Foreign Application Priority Data
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Nov 25, 2015 [KR] |
|
|
10-2015-0165741 |
|
Current U.S.
Class: |
1/1 |
Current CPC
Class: |
H01L
51/0067 (20130101); H01L 51/0054 (20130101); H01L
51/0056 (20130101); H01L 51/0058 (20130101); H01L
51/0052 (20130101); H01L 27/3209 (20130101); H01L
51/5076 (20130101); H01L 51/5044 (20130101); H01L
51/5072 (20130101) |
Current International
Class: |
H01L
51/00 (20060101); H01L 51/50 (20060101) |
Field of
Search: |
;428/690 |
References Cited
[Referenced By]
U.S. Patent Documents
Foreign Patent Documents
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103165817 |
|
Jun 2013 |
|
CN |
|
104507927 |
|
Apr 2015 |
|
CN |
|
104716268 |
|
Apr 2015 |
|
CN |
|
2012-82136 |
|
Apr 2012 |
|
JP |
|
WO 2015/152633 |
|
Oct 2015 |
|
WO |
|
Primary Examiner: Truong; Duc
Attorney, Agent or Firm: Birch, Stewart, Kolasch &
Birch, LLP
Claims
What is claimed is:
1. An organic light emitting display device comprising: at least
one light emitting part between an anode and a cathode and
including at least one organic layer and a light emitting layer,
wherein the at least one organic layer includes an organic
compound, and the organic compound includes a triazine compound
having a substituent with a steric effect, wherein the organic
compound is represented by the following Chemical Formula 1:
##STR00116## wherein A includes one among hydrogen and a phenyl
group, R.sub.1 and R.sub.3 include independently one among hydrogen
and an aryl group of 10 to 30 carbon atoms, R.sub.2 includes one
among hydrogen and an aryl group of 10 to 30 carbon atoms when A is
hydrogen, R.sub.2 includes hydrogen when A is phenyl, with at least
one among R.sub.1 to R.sub.3 being an aryl group, except for the
case that R.sub.1 to R.sub.3 are all hydrogen, and wherein the
organic compound represented by Chemical Formula 1 excludes the
following compounds: ##STR00117##
2. The organic light emitting display device of claim 1, wherein
the at least one organic layer includes an electron transport
layer.
3. The organic light emitting display device of claim 1, wherein
the organic compound has an asymmetrical substitution form around
the triazine compound.
4. The organic light emitting display device of claim 1, wherein
the substituent includes an aryl group having at least 10 or more
carbon atoms.
5. The organic light emitting display device of claim 1, wherein
the at least one light emitting part includes at least two or more
light emitting parts, and one of the at least two or more light
emitting parts is a blue light emitting part and the another one of
the at least two or more light emitting parts is a yellow-green
light emitting part.
6. The organic light emitting display device of claim 1, wherein
R.sub.1 to R.sub.3 include independently one among the following
compounds: ##STR00118## ##STR00119##
7. The organic light emitting display device of claim 1, wherein
the organic compound represented by Chemical Formula 1 includes one
among the following compounds: ##STR00120## ##STR00121##
##STR00122## ##STR00123## ##STR00124## ##STR00125## ##STR00126##
##STR00127## ##STR00128## ##STR00129## ##STR00130## ##STR00131##
##STR00132## ##STR00133## ##STR00134## ##STR00135## ##STR00136##
##STR00137## ##STR00138## ##STR00139## ##STR00140## ##STR00141##
##STR00142## ##STR00143## ##STR00144## ##STR00145## ##STR00146##
##STR00147##
8. The organic light emitting display device of claim 2, wherein
the electron transport layer further includes a dopant, and the
dopant includes one among an alkali metal, an alkali earth metal,
an alkali metal compound, an alkali earth metal compound, an
organic complex of alkali metals, or an organic complex of alkali
earth metals.
9. An organic light emitting display device comprising: at least
one light emitting part between an anode and a cathode and
including at least one organic layer and a light emitting layer,
wherein the at least one organic layer includes an organic compound
represented by the following Chemical Formula 1: ##STR00148##
wherein A includes one among hydrogen and a phenyl group, R.sub.1
and R.sub.3 include independently one among hydrogen and an aryl
group of 10 to 30 carbon atoms, R.sub.2 includes one among hydrogen
and an aryl group of 10 to 30 carbon atoms when A is hydrogen,
R.sub.2 includes hydrogen when A is phenyl, with at least one among
R.sub.1 to R.sub.3 being an aryl group, except for the case that
R.sub.1 to R.sub.3 are all hydrogen, and wherein the organic
compound represented by Chemical Formula 1 excludes the following
compounds: ##STR00149##
10. The organic light emitting display device of claim 9, wherein
R.sub.1 to R.sub.3 include independently one among the following
compounds: ##STR00150## ##STR00151##
11. The organic light emitting display device of claim 9, wherein
the organic compound represented by Chemical Formula 1 includes one
among the following compounds: ##STR00152## ##STR00153##
##STR00154## ##STR00155## ##STR00156## ##STR00157## ##STR00158##
##STR00159## ##STR00160## ##STR00161## ##STR00162## ##STR00163##
##STR00164## ##STR00165## ##STR00166## ##STR00167## ##STR00168##
##STR00169## ##STR00170## ##STR00171## ##STR00172## ##STR00173##
##STR00174## ##STR00175## ##STR00176## ##STR00177## ##STR00178##
##STR00179##
Description
This application claims the priority benefit of Korean Patent
Application No. 10-2015-0165741 filed on Nov. 25, 2015, which is
incorporated herein by reference for all purposes as if fully set
forth herein.
BACKGROUND
Field of the Invention
The present disclosure relates to an organic light emitting display
device, and more particularly, to an organic light emitting display
device which can reduce operating voltage and improve quantum
efficiency and lifetime.
Discussion of the Related Art
Image displays used for displaying a variety of information on the
screen are one of the core technologies of the information and
communication era. Such image displays have been developed to be
thinner, lighter, and more portable, and furthermore to have high
performance. With the development of the information society,
various demands for display devices are on the rise. To meet these
demands, research on panel displays such as liquid crystal displays
(LCD), plasma display panels (PDP), electroluminescent displays
(ELD), field emission displays (FED), organic light emitting diodes
(OLED), etc. is actively under way.
Among these types of flat panel displays, the OLED devices are
advantageous in that they can be fabricated on a flexible substrate
such as plastic, operate at a low voltage of 10 V or less, have
lower power consumption, and deliver vivid color reproduction, as
compared with plasma display panels or inorganic light emitting
displays. Also, the organic light emitting display devices are
spotlighted as the next-generation display devices that provide
rich colors for its ability to render full color images using three
colors--red, green, and blue.
An organic light emitting display device can be formed by
sequentially stacking an anode, a hole injection layer, a hole
transport layer, a light emitting layer, an electron transport
layer, an electron injection layer, and a cathode. An exciton is
formed by the recombination of electrons and holes injected from
the two electrodes. A singlet exciton is involved in fluorescence,
and a triplet exciton is involved in phosphorescence. Recently, a
shift from fluorescent materials to phosphorescent materials is
taking place. This is because the fluorescent materials can only
use about 25% singlet excitions formed in a light emitting layer to
generate light, with 75% triplet excitons lost as heat, whereas the
phosphorescent materials have a luminescence mechanism that
converts all the excitons into light.
A luminescence process of a phosphorescence light emitting diode
will be explained briefly. Holes injected from the anode and
electrons injected from the cathode meet at the host material of
the light emitting layer. That is, electron and hole pairs mostly
meet at the host because of the high concentration of the host
although some of them meet at the dopant. In this instance, the
singlet excitons formed at the host undergo an energy transition to
a singlet or triplet state of the dopant, and the triplet excitons
undergo an energy transition to a triplet state of the dopant.
Because the excitons transferred to the singlet state of the dopant
are then transferred to the triplet state of the dopant by
intersystem crossing, the first destination for all the excitons is
a triplet level of the dopant. These excitons formed are
transferred to a ground state and generate light. In this case, if
the triplet energy of a hole transport layer or electron transport
layer adjacent to the front or back of the light emitting layer is
lower than the triplet energy of the dopant, a reverse energy
transition takes place from the dopant or host to the hole
transport layer or electron transport layer, which results in a
significant decrease in efficiency. Accordingly, the triplet energy
of the hole/electron transport layers, as well as that of the host
material of the light emitting layer, plays a highly important role
in phosphorescent light emitting diodes.
In order to stably run an organic light emitting display device, it
is important that holes injected from the anode and electrons
injected from the cathode form excitons while maintaining charge
balance in the light emitting layer. However, an excess of holes
are left after the exciton formation because the holes have faster
mobility than the electrons, and this excess of holes generate
charged polarons in the light emitting layer or electron transport
layer, thus making the device unstable due to exciton-polaron
quenching, etc. In this regard, there are ongoing studies to
improve the efficiency and lifetime of organic light emitting
display devices by maintaining charge balance in the light emitting
layer.
SUMMARY
Accordingly, the present disclosure is directed to an organic light
emitting display device which can improve its efficiency and
lifetime.
To achieve these and other advantages and in accordance with the
purpose of the disclosure, as embodied and broadly described, an
exemplary embodiment of the present disclosure provides an organic
light emitting display device comprising at least one light
emitting part between an anode and a cathode and comprising at
least one organic layer and a light emitting layer, wherein the
organic layer comprises an organic compound, and the organic
compound includes a triazine compound having a substituent with a
steric effect.
The organic layer includes an electron transport layer. The organic
compound has an asymmetrical substitution form around the triazine
compound. The substituent includes an aryl group of at least 10 or
more carbon atoms.
The light emitting part comprises at least two or more light
emitting parts, and one of the light emitting parts is a blue light
emitting part and the another one of the light emitting parts is a
yellow-green light emitting part.
The organic compound is represented by the following Chemical
Formula 1:
##STR00001## wherein A includes one among hydrogen and a phenyl
group, R.sub.1 to R.sub.3 include independently one among hydrogen
and an aryl group of 10 to 30 carbon atoms, with at least one among
R.sub.1 to R.sub.3 being an aryl group, except for the case that
R.sub.1 to R.sub.3 are all hydrogen.
Further, R.sub.1 to R.sub.3 include independently one among the
following compounds:
##STR00002## ##STR00003##
The organic compound represented by Chemical Formula 1 includes one
among the following compounds:
##STR00004## ##STR00005## ##STR00006## ##STR00007## ##STR00008##
##STR00009## ##STR00010## ##STR00011## ##STR00012## ##STR00013##
##STR00014## ##STR00015## ##STR00016## ##STR00017## ##STR00018##
##STR00019## ##STR00020## ##STR00021## ##STR00022## ##STR00023##
##STR00024## ##STR00025## ##STR00026## ##STR00027## ##STR00028##
##STR00029## ##STR00030## ##STR00031## ##STR00032## ##STR00033##
##STR00034## ##STR00035##
The electron transport layer further includes a dopant, and the
dopant includes one among an alkali metal, an alkali earth metal,
an alkali metal compound, an alkali earth metal compound, an
organic complex of alkali metals, or an organic complex of alkali
earth metals.
At least one light emitting part between an anode and a cathode may
include at least one organic layer and a light emitting layer,
wherein the organic layer comprises an organic compound represented
by the following Chemical Formula 1:
##STR00036## wherein A includes one among hydrogen and a phenyl
group, R.sub.1 to R.sub.3 include independently one among hydrogen
and an aryl group of 10 to 30 carbon atoms, with at least one among
R.sub.1 to R.sub.3 being an aryl group, except for the case that
R.sub.1 to R.sub.3 are all hydrogen.
Further, R.sub.1 to R.sub.3 include independently one among the
following compounds:
##STR00037## ##STR00038##
The organic compound represented by Chemical Formula 1 includes one
among the following compounds:
##STR00039## ##STR00040## ##STR00041## ##STR00042## ##STR00043##
##STR00044## ##STR00045## ##STR00046## ##STR00047## ##STR00048##
##STR00049## ##STR00050## ##STR00051## ##STR00052## ##STR00053##
##STR00054## ##STR00055## ##STR00056## ##STR00057## ##STR00058##
##STR00059## ##STR00060## ##STR00061## ##STR00062## ##STR00063##
##STR00064## ##STR00065## ##STR00066## ##STR00067## ##STR00068##
##STR00069## ##STR00070##
BRIEF DESCRIPTION OF THE DRAWINGS
The accompanying drawings, which are included to provide a further
understanding of the disclosure and are incorporated in and
constitute a part of this specification, illustrate embodiments of
the disclosure and together with the description serve to explain
the principles of the disclosure. In the drawings:
FIG. 1 is a view showing an organic light emitting display device
according to a first exemplary embodiment of the present
disclosure;
FIG. 2 is a view showing an organic light emitting display device
according to a second exemplary embodiment of the present
disclosure; and
FIG. 3 is a view showing an organic light emitting display device
according to a third exemplary embodiment of the present
disclosure.
DETAILED DESCRIPTION
The advantages and features of the present disclosure and methods
for accomplishing the same may be understood more readily by
reference to the following detailed descriptions of exemplary
embodiments and the accompanying drawings. The present disclosure
may, however, be embodied in many different forms and should not be
construed as being limited to the exemplary embodiments set forth
herein. Rather, these exemplary embodiments are provided so that
this disclosure will be thorough and complete and will fully convey
the concept of the present disclosure to those skilled in the art,
and the present disclosure is defined by the appended claims
The shapes, sizes, percentages, angles, numbers, etc. shown in the
figures to describe the exemplary embodiments of the present
disclosure are merely examples and not limited to those shown in
the figures. Like reference numerals denote like elements
throughout the specification. In describing the present disclosure,
detailed descriptions of related well-known technologies will be
omitted to avoid unnecessary obscuring the present disclosure. When
the terms `comprise`, `have`, `consist of` and the like are used,
other parts may be added as long as the term `only` is not used.
The singular forms may be interpreted as the plural forms unless
explicitly stated.
The elements may be interpreted to include an error margin even if
not explicitly stated.
When the position relation between two parts is described using the
terms `on`, `over`, `under`, `next to` and the like, one or more
parts may be positioned between the two parts as long as the term
`immediately` or `directly` is not used.
When the temporal relationship between two events is described
using the terms `after`, `following`, `next`, `before` and the
like, the two events may not occur in succession as long as the
term `immediately` or `directly` is not used.
It will be understood that, although the terms first, second, etc.,
may be used to describe various elements, these elements should not
be limited by these terms. These terms are only used to distinguish
one element from another element. Thus, a first element discussed
below could be termed a second element without departing from the
technical spirit of the present disclosure.
The features of various exemplary embodiments of the present
disclosure may be combined with one another partly or wholly, and
may technically interact or work together in various ways. The
exemplary embodiments may be carried out independently or in
combination with one another.
Hereinafter, various exemplary embodiments of the present
disclosure will be described in detail with reference to the
accompanying drawings.
FIG. 1 is a view showing an organic light emitting display device
according to a first exemplary embodiment of the present
disclosure. All the components of the organic light emitting
display devices according to all the embodiments of the present
disclosure are operatively coupled and configured.
Referring to FIG. 1, an organic light emitting display device 100
according to the first exemplary embodiment of the present
disclosure comprises an anode 110, a hole injection layer 120, a
hole transport layer 130, a light emitting layer 140, an electron
transport layer 150, an electron injection layer 210, and a cathode
220.
The anode 110 is a hole injection electrode, and may be formed of
one among ITO (indium tin oxide), IZO (indium zinc oxide), or ZnO
(zinc oxide) having a high work function. Also, if the anode 110 is
a reflective electrode, the anode 110 may further comprise a
reflective layer formed of one among aluminum (Al), silver (Ag), or
nickel (Ni) under a layer formed of one among ITO, IZO, or ZnO.
The hole injection layer 120 may function to facilitate hole
injection from the anode 110 to the light emitting layer 140, and
may be formed of, but is not limited to, one or more among CuPc
(copper phthalocyanine), PEDOT (poly(3,4)-ethylenedioxythiophene),
PANI (polyaniline), DNTPD
(N.sup.1,N.sup.1'-(biphenyl-4,4'-diyl)bis(N.sup.1-phenyl-N.sup.4,N.sup.4--
di-m-tolylbenzene-1,4-diamine), and
NPD(N,N'-bis(naphthalene-1-yl)-N,N'-bis(phenyl)-2,2'-dimethylbenzidine).
The hole injection layer 120 may have a 1 to 150 nm thickness. If
the hole injection layer 120 has a 1 nm thickness or greater, the
hole injection properties may be improved, or if the hole injection
layer 120 has a 150 nm thickness or less, an increase in the
thickness of the hole injection layer 120 may be prevented and a
rise in operating voltage may be therefore prevented. The hole
injection layer 120 may not be included in the elements of the
organic light emitting display device, depending on the structure
or characteristics of the organic light emitting display
device.
The hole transport layer 130 may function to facilitate hole
transport, and may be formed of, but is not limited to, one or more
among
NPD(N,N'-bis(naphthalene-1-yl)-N,N'-bis(phenyl)-2,2'-dimethylbenzidine),
TPD(N,N'-bis-(3-methylphenyl)-N,N'-bis(phenyl)-benzidine),
spiro-TAD(2,2'7,7'-tetrakis(N,N-diphenylamino)-9,9'-spirofluorene),
NPB(N,N'-bis(naphthalene-1-yl-N,N'-bis(phenyl)-benzidine), and
MTDATA(4,4',4''-Tris(N-3-methylphenyl-N-phenylamino)-triphenylamine).
The hole transport layer 130 may have a 1 to 150 nm thickness. If
the hole transport layer 130 has a 1 nm thickness or greater, the
hole transport properties may be improved, or if the hole transport
layer 130 has a 150 nm thickness or less, an increase in the
thickness of the hole transport layer 130 may be prevented, and a
rise in operating voltage may be therefore prevented. Also, an
electron blocking layer may be further formed over the hole
transport layer 130.
The light emitting layer 140 may emit light of red (R), green (G),
or blue (B), and may be formed of a fluorescent material or
phosphorescent material.
If the light emitting layer 140 is a red light emitting layer, it
may be formed of, but is not limited to, a fluorescent material
comprising PBD:Eu(DBM).sub.3(Phen) or perylene. If the light
emitting layer 140 is a green light emitting layer, it may be
formed of, but is not limited to, a fluorescent material comprising
Alq.sub.3(tris(8-hydroxyquinolinato)aluminum). If the light
emitting layer 140 is a blue light emitting layer, it may be formed
of, but is not limited to, a fluorescent material comprising one
among
spiro-BDAVBi(2,7-bis[4-diphenylamino)styryl]-9,9-spirofluorene),
spiro-CBP(2,2',7,7'-tetrakis(carbozol-9-yl)-9,9-spirofluorene),
distyrylbenzene (DSB), distyrylarylene (DSA), a polyfluorene (PFO)
polymer, and a polyphenylenevinylene (PPV) polymer.
In the organic light emitting display device, the electron
transport layer 150 is on the light emitting layer 140. The
electron transport layer 150 is formed of a material that has
electron transport properties, with high electron mobility, to
facilitate electron transport. Also, the electron transport layer
150 is required to have an amorphous structure in order to stably
run the device. If the electron transport layer 150 has a
crystalline structure, a crystallized part of a thin film acts as a
path through which current can easily move. That is, when a current
is concentrated at the crystallized part of the thin film, decay
occurs rapidly at the crystallized part of the thin film. Decay of
the electron transport layer 150 leads to a decrease in the
lifetime of the organic light emitting display device. Accordingly,
the present inventors conducted several tests or experiments to
prevent a decrease in the device's lifetime and improve the
device's efficiency by forming an electron transport layer 150
formed of a material with an amorphous structure and high electron
mobility.
Through a number of tests or experiments which were performed on
materials that do not affect the lifetime or efficiency of the
organic light emitting display device and that cause no rise in
operating voltage, the present inventors developed organic
compounds that have an amorphous structure and provide electron
transport properties with the use of a single material. An organic
compound of this disclosure comprises p-biphenyl triazine as a core
to form an electron transport layer. The LUMO (lowest unoccupied
molecular orbital) energy level of a p-biphenyl triazine compound
is concentrated in the p-biphenyl triazine groups, and this
facilitates electron movement between neighboring p-biphenyl
triazine groups within a molecular stack through this LUMO energy
level, thereby improving electron mobility.
Moreover, an organic compound of this disclosure includes an aryl
group of at least 10 or more carbon atoms with high steric effect,
which is a substituent, and has an asymmetrical substitution form
around a triazine, in order to have an amorphous structure by
eliminating coplanarity and reducing symmetry. By forming an
electron transport layer 150 formed of an organic compound with an
amorphous structure according to the present disclosure, decay of
the electron transport layer 150 may be prevented.
Accordingly, the electron transport layer 150 of this disclosure
comprises an organic compound represented by the following Chemical
Formula 1:
##STR00071##
wherein A includes one among hydrogen and a phenyl group, R.sub.1
to R.sub.3 include independently one among hydrogen and an aryl
group of 10 to 30 carbon atoms, with at least one among R.sub.1 to
R.sub.3 being an aryl group, except for the case that R.sub.1 to
R.sub.3 are all hydrogen.
Further, R.sub.1 to R.sub.3 may be independently one among the
following compounds:
##STR00072## ##STR00073##
The organic compound of this disclosure represented by Chemical
Formula 1 may be one among the following compounds:
##STR00074## ##STR00075## ##STR00076## ##STR00077## ##STR00078##
##STR00079## ##STR00080## ##STR00081## ##STR00082## ##STR00083##
##STR00084## ##STR00085## ##STR00086## ##STR00087## ##STR00088##
##STR00089## ##STR00090## ##STR00091## ##STR00092## ##STR00093##
##STR00094## ##STR00095## ##STR00096## ##STR00097## ##STR00098##
##STR00099## ##STR00100## ##STR00101## ##STR00102## ##STR00103##
##STR00104## ##STR00105##
An organic compound of this disclosure comprises p-biphenyl
triazine as a core to facilitate electron movement between
neighboring p-biphenyl triazine groups within the molecular stack
in the electron transport layer. Moreover, an organic compound of
this disclosure includes an aryl group of at least 10 or more
carbon atoms with high steric effect, which is a substituent, and
has an asymmetrical substitution form around a triazine, in order
to have an amorphous structure by eliminating coplanarity and
reducing symmetry.
Accordingly, the electron transport layer is formed of an organic
compound of this disclosure to improve electron mobility, thereby
reducing the operating voltage of the device and improving the
efficiency. Also, the organic compound of this disclosure may
prevent decay of the electron transport layer for its amorphous
structure.
The electron transport layer 150 further comprises a dopant. The
dopant may be one among an alkali metal, an alkali earth metal, an
alkali metal compound, an alkali earth metal compound, an organic
complex of alkali metals, or an organic complex of alkali earth
metals. For example, the electron transport layer 150 may further
comprise Liq. The aforementioned dopant may improve the electron
injection capability of the electron transport layer 150 for its
high affinity for electrons. The percentage of the dopant may be 10
to 90% by weight of the total weight of electron transport layer
150.
The electron transport layer 150 may have a 1 to 150 nm thickness.
If the electron transport layer 150 has a 1 nm thickness or
greater, a degradation of the electron transport properties may be
prevented, or if the electron transport layer 150 has a 150 nm
thickness or less, an increase in the thickness of the electron
transport layer 150 may be prevented, and a rise in operating
voltage may be therefore prevented.
The electron injection layer 210 functions to facilitate electron
injection, and may be formed of, but is not limited to, one among
Alq.sub.3 (tris(8-hydroxyquinolinato)aluminum),
PBD(2-4-biphenyl)-5-(4-tert-butylphenyl)-1,3,4-oxadiazole),
TAZ(3-(4-biphenyl)-4-pheynyl-5-tert-butylphenyl-1,2,4-triazole),
and
BAlq(Bis(2-methyl-8-quinolinolato)-4-(phenylphenolato)aluminum). On
the other hand, the electron injection layer 210 may be formed of a
metal compound, and the metal compound may be, for example, but is
not limited to, one or more among
8-hydroxyquinolinolato-lithium(Liq), LiF, NaF, KF, RbF, CsF, FrF,
BeF.sub.2, MgF.sub.2, CaF.sub.2, SrF.sub.2, BaF.sub.2, and
RaF.sub.2. The electron injection layer 210 may have a 1 to 50 nm
thickness. If the electron injection layer 210 has a nm thickness
or greater, a degradation of the electron injection properties may
be prevented, or if the electron injection layer 210 has a 50 nm
thickness or less, an increase in the thickness of the electron
injection layer 210 may be prevented, and a rise in operating
voltage may be therefore prevented.
The cathode 220 is an electron injection electrode, and may be
formed of magnesium (Mg), calcium (Ca), aluminum (Al), silver (Ag),
or an alloy thereof, having a low work function. If the organic
light emitting display device is a top-emission type or a
dual-emission type, the cathode 220 may be formed thin enough to
pass light therethrough. If the organic light emitting display
device is a bottom-emission type, the cathode 220 may be formed
thick enough to reflect light.
An electron transport layer comprising the above-described organic
compound of this disclosure is not limited to phosphorescent or
fluorescence, but may be included in all types of organic light
emitting display devices.
As stated above, an organic compound of this disclosure comprises
p-biphenyl triazine as a core to facilitate electron movement
between neighboring p-biphenyl triazine groups within the molecular
stack of the electron transport layer. Moreover, an organic
compound of this disclosure includes an aryl group of at least 10
or more carbon atoms with high steric effect, which is a
substituent, and has an asymmetrical substitution form around a
triazine, in order to have an amorphous structure by eliminating
coplanarity and reducing symmetry.
Accordingly, the electron transport layer is formed of an organic
compound of this disclosure to improve electron mobility, thereby
reducing the operating voltage of the device and improving the
efficiency. Also, the organic compound of this disclosure may
prevent decay of the electron transport layer for its amorphous
structure.
FIG. 2 is a view showing an organic light emitting display device
according to a second exemplary embodiment of the present
disclosure. The same elements as the first exemplary embodiment are
denoted by the same reference numerals, so descriptions of these
elements will be omitted or brief below.
Referring to FIG. 2, an organic light emitting display device 100
of the present disclosure comprises light emitting parts ST1 and
ST2 between an anode 110 and a cathode 220, and a charge generation
layer 160 between the light emitting parts ST1 and ST2.
The first light emitting part ST1 comprises a first light emitting
layer 140. The first light emitting layer 140 may emit light of red
(R), green (G), or blue (B), and may be formed of a fluorescent
material. In this exemplary embodiment, the first light emitting
layer 140 may be a blue light emitting layer. The blue light
emitting layer comprises one among a blue light emitting layer, a
dark blue light emitting layer, and a sky blue light emitting
layer. Alternatively, the first light emitting layer 140 may be
formed of a blue light emitting layer and a red light emitting
layer, of a blue light emitting layer and a yellow-green light
emitting layer, or of a blue light emitting layer and a green light
emitting layer.
The first light emitting part ST1 comprises a hole injection layer
120 and a first hole transport layer 130 that are between the anode
110 and the first light emitting layer 140, and a first electron
transport layer 150 on the first light emitting layer 140.
Accordingly, the first light emitting part ST1 comprising the hole
injection layer 120, the first hole transport layer 130, the first
light emitting layer 140, and the first electron transport layer
150 is formed on the anode 110. The hole injection layer 120 may
not be included in the elements of the first light emitting part
ST1, depending on the structure or characteristics of the
device.
The first electron transport layer 150 has the same composition as
the above-described electron transport layer of the first exemplary
embodiment. The first electron transport layer 150 comprises
p-biphenyl triazine as a core to facilitate electron movement
between neighboring p-biphenyl triazine groups within the molecular
stack of the electron transport layer. Moreover, an organic
compound of this disclosure includes an aryl group of at least 10
or more carbon atoms with high steric effect, which is a
substituent, and has an asymmetrical substitution form around a
triazine, in order to have an amorphous structure by eliminating
coplanarity and reducing symmetry. Accordingly, the electron
transport layer is formed of an organic compound of this disclosure
to improve electron mobility, thereby reducing the operating
voltage of the device and improving the efficiency. Also, the
organic compound of this disclosure may prevent decay of the
electron transport layer for its amorphous structure.
A charge generation layer (CGL) 160 is between the first light
emitting part ST1 and the second light emitting part ST2. The first
light emitting part ST1 and the second light emitting part ST2 are
connected by the charge generation layer 160. The charge generation
layer 160 may be a PN-junction charge generation layer formed by
joining an N-type charge generation layer 160N and a P-type charge
generation layer 160P. The PN junction charge generation layer 160
generates a charge, or injects the charge, i.e., electrons and
holes, separately into the light emitting layer. That is, the
N-type charge generation layer 160N transfers electrons to the
first electron transport layer 150, the first electron transport
layer 150 supplies the electrons to the first light emitting layer
140 adjacent to the anode, and the P-type charge generation layer
160P transfers holes to the second hole transport layer 180 to
supply the holes to the second light emitting layer 190 of the
second light emitting part ST2. As such, the light emission
efficiency of the first and second light emitting layers 140 and
190 may be further increased, and the operating voltage may be
reduced.
The N-type charge generation layer 160N may be formed of a metal or
N-type-doped organic material. The metal may be one material among
Li, Na, K, Rb, Cs, Mg, Ca, Sr, Ba, La, Ce, Sm, Eu, Tb, Dy, and Yb.
An N-type dopant and host for the N-doped organic material may be
generally-used materials. For example, the N-type dopant may be an
alkali metal, an alkali metal compound, an alkali earth metal, or
an alkali earth metal compound. Specifically, the N-type dopant may
be one among Li, Cs, K, Rb, Mg, Na, Ca, Sr, Eu, and Yb. The
percentage of the dopant to be mixed is between 1% and 8% by weight
relative to 100% for the host. The dopant may have a work function
of 2.5 eV or greater. The host material may be an organic material
of 20 to 60 carbon atoms that has a hetero ring with nitrogen
atoms, for example, one among
Alq.sub.3(tris(8-hydroxyquinoline)aluminum), a triazine derivative,
a hydroxyquinoline derivative, a benzazole derivative, and a silole
derivative.
The P-type charge generation layer 160P may be formed of a metal or
a P-doped organic material. The metal may be one or more alloys
among Al, Cu, Fe, Pb, Zn, Au, Pt, W, In, Mo, Ni, and Ti. A P-type
dopant and host for the P-doped organic material may be the
following materials. For example, the P-type dopant may be one
material among
F.sub.4-TCNQ(2,3,5,6-tetrafluoro-7,7,8,8-tetracyanoquinodimethane),
a derivative of tetracyanoquinodimethane, iodine, FeCl.sub.3,
FeF.sub.3, and SbCl.sub.5. The host may be one material among NPB
(N,N'-bis(naphthalene-1-yl)-N,N'-bis(phenyl)-benzidine),
TPD(N,N'-bis-(3-methylphenyl)-N,N'-bis(phenyl)-benzidine), and
TNB(N,N,N'N'-tetranaphthalenyl-benzidine).
The second light emitting part ST2 comprising a second hole
transport layer 180, the second light emitting layer 190, a second
electron transport layer 200, and an electron injection layer 210
is on the charge generation layer 160.
The second light emitting layer 190 may emit light of red (R),
green (G), blue (B), or yellow-green (YG), and may be formed of a
phosphorescent material. In this exemplary embodiment, the second
light emitting layer 190 may be a light emitting layer that emits
yellow-green light. The second light emitting layer 190 may have a
single layer structure of a yellow-green light emitting layer or
green light emitting layer, or a multilayer structure formed of a
yellow-green light emitting layer and a green light emitting layer.
The second light emitting layer 190 comprises a yellow-green light
emitting layer, a green light emitting layer, or a multilayer
structure formed of a yellow-green light emitting layer and a green
light emitting layer, of a yellow light emitting layer and a red
light emitting layer, of a green light emitting layer and a red
light emitting layer, or of a yellow-green light emitting layer and
a red light emitting layer.
This exemplary embodiment will be described by taking as an example
a single layer structure of a second light emitting layer 190 that
emits yellow-green light. The second light emitting layer 190 may
include, but is not limited to, at least one host of CBP
4,4'-bis(carbazol-9-yl)biphenyl) or
BAlq(Bis(2-methyl-8-quinolinolato)-4-(phenylphenolato)aluminum) and
a phosphorescent yellow-green dopant that emits yellow-green
light.
The second light emitting part ST2 comprises the second hole
transport layer 180 between the charge generation layer 160 and the
second light emitting layer 190, and comprises the second electron
transport layer 200 and electron injection layer 210 on the second
light emitting layer 190. The second hole transport layer 180 may
have the same composition as the first hole transport layer 130 of
the first light emitting part ST1 or have a different composition
from that of the first hole transport layer 130.
The second electron transport layer 200 has the same composition as
the aforementioned first electron transport layer 150. The second
electron transport layer 200 comprises p-biphenyl triazine as a
core to facilitate electron movement between neighboring p-biphenyl
triazine groups within the molecular stack of the electron
transport layer. Moreover, an organic compound of this disclosure
includes an aryl group of at least 10 or more carbon atoms with
high steric effect, which is a substituent, and has an asymmetrical
substitution form around a triazine, in order to have an amorphous
structure by eliminating coplanarity and reducing symmetry.
Accordingly, the electron transport layer is formed of an organic
compound of this disclosure to improve electron mobility, thereby
reducing the operating voltage of the device and improving the
efficiency. Also, the organic compound of this disclosure may
prevent decay of the electron transport layer for its amorphous
structure.
Accordingly, the second light emitting part ST2 comprising the
second hole transport layer 180, the second light emitting layer
190, the second electron transport layer 200, and the electron
injection layer 210 is formed on the charge generation layer 160.
The cathode 220 is provided on the second light emitting part ST2
to constitute the organic light emitting display device according
to the second exemplary embodiment of the present disclosure.
The above-described second exemplary embodiment of the present
disclosure has disclosed that the first electron transport layer
150 and the second electron transport layer 200 comprise an organic
compound of this disclosure. Alternatively, at least one of the
first and second electron transport layers 150 and 200 may comprise
the organic compound of this disclosure.
As stated above, an organic compound of this disclosure comprises
p-biphenyl triazine as a core to facilitate electron movement
between neighboring p-biphenyl triazine groups within the molecular
stack of the electron transport layer. Moreover, an organic
compound of this disclosure includes an aryl group of at least 10
or more carbon atoms with high steric effect, which is a
substituent, and has an asymmetrical substitution form around a
triazine, in order to have an amorphous structure by eliminating
coplanarity and reducing symmetry. Accordingly, the electron
transport layer is formed of an organic compound of this disclosure
to improve electron mobility, thereby reducing the operating
voltage of the device and improving the efficiency. Also, the
organic compound of this disclosure may prevent decay of the
electron transport layer for its amorphous structure.
FIG. 3 is a view showing an organic light emitting display device
according to a third exemplary embodiment of the present
disclosure. The same elements as the first and/or second exemplary
embodiments are denoted by the same reference numerals, so
descriptions of these elements will be omitted or brief below.
Referring to FIG. 3, an organic light emitting display device 100
of the present disclosure comprises a plurality of light emitting
parts ST1, ST2, and ST3 between an anode 110 and a cathode 220, and
a first charge generation layer 160 and a second charge generation
layer 230 that are between the light emitting parts ST1, ST2, and
ST3. Although this exemplary embodiment has been illustrated and
described with an example where three light emitting parts are
between the anode 110 and the cathode 220, the present disclosure
is not limited to this example and four or more light emitting
parts may be between the anode 110 and the cathode 220.
Among the light emitting parts, the first light emitting part ST1
comprises a first light emitting layer 140. The first light
emitting layer 140 may emit light of red, green, or blue: for
example, it may be a blue light emitting layer in this exemplary
embodiment. The blue light emitting layer comprises one among a
blue light emitting layer, a dark blue light emitting layer, and a
sky blue light emitting layer. Alternatively, the first light
emitting layer 140 may be formed of a blue light emitting layer and
a red light emitting layer, of a blue light emitting layer and a
yellow-green light emitting layer, or of a blue light emitting
layer and a green light emitting layer.
The first light emitting part ST1 comprises a hole injection layer
120 and a first hole transport layer 130 that are between the anode
110 and the first light emitting layer 140, and a first electron
transport layer 150 on the first light emitting layer 140.
Accordingly, the first light emitting part ST1 comprising the hole
injection layer 120, the first hole transport layer 130, the first
light emitting layer 140, and the first electron transport layer
150 is formed on the anode 110. The hole injection layer 120 may
not be included in the elements of the first light emitting part
ST1, depending on the structure or characteristics of the
device.
The first electron transport layer 150 has the same composition as
the aforementioned first electron transport layers 150 of the first
and second exemplary embodiments. The organic compound of this
disclosure used as the first electron transport layer 150 comprises
p-biphenyl triazine as a core to facilitate electron movement
between neighboring p-biphenyl triazine groups within the molecular
stack of the electron transport layer. Moreover, an organic
compound of this disclosure includes an aryl group of at least 10
or more carbon atoms with high steric effect, which is a
substituent, and has an asymmetrical substitution form around a
triazine, in order to have an amorphous structure by eliminating
coplanarity and reducing symmetry. Accordingly, the electron
transport layer is formed of an organic compound of this disclosure
to improve electron mobility, thereby reducing the operating
voltage of the device and improving the efficiency. Also, the
organic compound of this disclosure may prevent decay of the
electron transport layer for its amorphous structure.
The second light emitting part ST2 comprising a second light
emitting layer 190 is on the first light emitting part ST1. The
second light emitting layer 190 may emit light of red, green, blue,
or yellow-green: for example, it may be a yellow-green light
emitting layer in this exemplary embodiment. The second light
emitting layer 190 may comprise a yellow-green light emitting
layer, a green light emitting layer, or a multilayer structure
formed of a yellow-green light emitting layer and a green light
emitting layer, of a yellow light emitting layer and a red light
emitting layer, of a green light emitting layer and a red light
emitting layer, or of a yellow-green light emitting layer and a red
light emitting layer. The second light emitting part ST2 further
comprises a second hole transport layer 180 on the first light
emitting part ST1, and comprises a second electron transport layer
200 on the second light emitting layer 190. Accordingly, the second
light emitting part ST2 comprising the second hole transport layer
180, the second light emitting layer 190, and the second electron
transport layer 200 is formed on the first light emitting part
ST1.
The second electron transport layer may have the same composition
as the above-described first electron transport layer 150. That is,
the second electron transport layer 200 may comprise a compound of
this disclosure. A detailed description of this has been given
previously, so it will be omitted.
A first charge generation layer 160 is between the first light
emitting part ST1 and the second light emitting part ST2. The first
charge generation layer 160 is a PN-junction charge generation
layer formed by joining an N-type charge generation layer 160N and
a P-type charge generation layer 160P. The first charge generation
layer 160 generates a charge, or injects the charge, i.e.,
electrons and holes, separately into the first and second light
emitting layers 140 and 190.
The third light emitting part ST3 comprising a third light emitting
layer 250 is on the second light emitting part ST2. The third light
emitting layer 250 may emit light of red, green, or blue, and be
formed of a fluorescent material. For example, it may be a blue
light emitting layer in this exemplary embodiment. The blue light
emitting layer comprises one among a blue light emitting layer, a
dark blue light emitting layer, and a sky blue light emitting
layer. Alternatively, the third light emitting layer 250 may be
formed of a blue light emitting layer and a red light emitting
layer, of a blue light emitting layer and a yellow-green light
emitting layer, or of a blue light emitting layer and a green light
emitting layer.
The third light emitting part ST3 further comprises a third hole
transport layer 240 on the second light emitting part ST2, and a
third electron transport layer 260 and an electron injection layer
210 that are on the third light emitting layer 250.
The third electron transport layer 260 has the same composition as
the aforementioned first electron transport layer 150. That is, the
third electron transport layer 260 may comprise a compound of this
disclosure. A detailed description of this has been given
previously, so it will be omitted.
The second charge generation layer 230 is between the second light
emitting part ST2 and the third light emitting part ST3. The second
charge generation layer 230 is a PN junction charge generation
layer formed by joining the N-type charge generation layer 230N and
the P-type charge generation layer 230P. The second charge
generation layer 230 generates a charge, or injects the charge,
i.e., electrons and holes, separately into the second and third
light emitting layers 190 and 250.
The cathode 220 is provided on the third light emitting part ST3 to
constitute the organic light emitting display device according to
the third exemplary embodiment of the present disclosure.
The third exemplary embodiment of the present disclosure has
disclosed that the first electron transport layer 150, the second
electron transport layer 200, and the third electron transport
layer 260 comprise an organic compound of this disclosure.
Alternatively, at least one among the first, second, and third
electron transport layers 150, 200, and 260 may comprise the
organic compound of this disclosure.
Organic light emitting displays using the organic light emitting
display device according to the third exemplary embodiment of the
present disclosure may include top emission displays, bottom
emission displays, dual emission displays, and vehicle lighting.
The vehicle lighting may include, but are not necessarily limited
to, headlights, high beams, taillights, brake lights, and back-up
lights. Moreover, organic light emitting displays using the organic
light emitting display device according to the second exemplary
embodiment of the present disclosure may be applied to mobile
devices, monitors, TVs, etc. In addition, organic light emitting
displays using the organic light emitting display device according
to the third exemplary embodiment of the present disclosure may be
applied to displays in which at least two of the first, second, and
third light emitting layers emit light of the same color.
As stated above, an organic compound of this disclosure comprises
p-biphenyl triazine as a core to facilitate electron movement
between neighboring p-biphenyl triazine groups within the molecular
stack of the electron transport layer. Moreover, an organic
compound of this disclosure includes an aryl group of at least 10
or more carbon atoms with high steric effect, which is a
substituent, and has an asymmetrical substitution form around a
triazine, in order to have an amorphous structure by eliminating
coplanarity and reducing symmetry. Accordingly, the electron
transport layer is formed of an organic compound of this disclosure
to improve electron mobility, thereby reducing the operating
voltage of the device and improving the efficiency. Also, the
organic compound of this disclosure may prevent decay of the
electron transport layer for its amorphous structure.
Hereinafter, synthesis examples of compounds of the present
disclosure will be described in detail. However, the following
examples are only for illustration, and the present disclosure is
not limited thereto.
1) Synthesis of Compound B-3
##STR00106##
2-chloro-4-(biphenyl-4-yl)-6-phenyl-1,3,5-triazine (4.5 g, 13.1
mmol),
4,4,5,5-tetramethyl-2-(3,5-bis(naphthalen-2-yl)phenyl)-1,3,2-dioxaborolan-
e (5.0 g, 11.0 mmol), tetrakistriphenylphosphine palladium (0)
(Pd(PPh3)4) (0.25 g, 0.22 mmol), 30 mL of 2M potassium carbonate
(K.sub.2CO.sub.3) solution, and 100 mL of tetrahydrofurane (THF)
were put into a 250-mL round-bottom flask under an argon
atmosphere, and then refluxed and stirred. Thin-layer
chromatography (TLC) was applied to monitor the completion of the
reaction, and then an organic layer was isolated from the reaction
solution and vacuum-distilled, followed by column chromatography,
to obtain Compound B-3.
2) Synthesis of Compound C-2
##STR00107##
2-chloro-4-(biphenyl-4-yl)-6-phenyl-1,3,5-triazine) (5.4 g, 15.8
mmol),
4,4,5,5-tetramethyl-2-(4-(phenanthren-10-yl)phenyl)-1,3,2-dioxaborolane
(5.0 g, 13.1 mmol), tetrakistriphenylphosphine palladium (0)
(Pd(PPh3)4) (0.30 g, 0.26 mmol), 35 mL of 2M potassium carbonate
(K.sub.2CO.sub.3) solution, and 100 mL of tetrahydrofurane (THF)
were put into a 250-mL round-bottom flask under an argon
atmosphere, and then refluxed and stirred. Thin-layer
chromatography (TLC) was applied to monitor the completion of the
reaction, and then an organic layer was isolated from the reaction
solution and vacuum-distilled, followed by column chromatography,
to obtain Compound C-2.
3) Synthesis of Compound G-3
##STR00108##
2-chloro-4-(biphenyl-4-yl)-6-phenyl-1,3,5-triazine) (3.5 g, 10.2
mmol),
2-(3,5-bis(9,9-dimethyl-9H-fluoren-2-yl)phenyl)-4,4,5,5-tetramethyl-1,3,2-
-dioxaborolane (5.0 g, 8.5 mmol), tetrakistriphenylphosphine
palladium (0) (Pd(PPh3)4) (0.20 g, 0.17 mmol), 25 mL of 2M
potassium carbonate (K.sub.2CO.sub.3) solution, and 100 mL of
tetrahydrofurane (THF) were put into a 250-mL round-bottom flask
under an argon atmosphere, and then refluxed and stirred.
Thin-layer chromatography (TLC) was applied to monitor the
completion of the reaction, and then an organic layer was isolated
from the reaction solution and vacuum-distilled, followed by column
chromatography, to obtain Compound G-3.
4) Synthesis of Compound G-6
##STR00109##
2,4-bis((1,1'-biphenyl)-4-yl)-6-chloro-1,3,5-triazine) (4.3 g, 10.2
mmol),
2-(3,5-bis(9,9-dimethyl-9H-fluoren-2-yl)phenyl)-4,4,5,5-tetramethy-
l-1,3,2-dioxaborolane (5.0 g, 8.5 mmol), tetrakistriphenylphosphine
palladium (0) (Pd(PPh3)4) (0.20 g, 0.17 mmol), 25 mL of 2M
potassium carbonate (K.sub.2CO.sub.3) solution, and 100 mL of
tetrahydrofurane (THF) were put into a 250-mL round-bottom flask
under an argon atmosphere, and then refluxed and stirred.
Thin-layer chromatography (TLC) was applied to monitor the
completion of the reaction, and then an organic layer was isolated
from the reaction solution and vacuum-distilled, followed by column
chromatography, to obtain Compound G-6.
5) Synthesis of Compound L-1
##STR00110##
2-chloro-4-(biphenyl-4-yl)-6-phenyl-1,3,5-triazine (3.2 g, 9.2
mmol),
4,4,5,5-tetramethyl-2-(3-(9,9-diphenyl-9H-fluoren-2-yl)phenyl)-1,3,2-diox-
aborolane (4.0 g, 7.7 mmol), tetrakistriphenylphosphine palladium
(0) (Pd(PPh3)4) (0.18 g, 0.15 mmol), 25 mL of 2M potassium
carbonate (K.sub.2CO.sub.3) solution, and 80 mL of tetrahydrofurane
(THF) were put into a 250-mL round-bottom flask under an argon
atmosphere, and then refluxed and stirred. Thin-layer
chromatography (TLC) was applied to monitor the completion of the
reaction, and then an organic layer was isolated from the reaction
solution and vacuum-distilled, followed by column chromatography,
to obtain Compound L-1.
6) Synthesis of Compound M-4
##STR00111##
2,4-bis((1,1'-biphenyl)-4-yl)-6-chloro-1,3,5-triazine (4.7 g, 11.2
mmol),
4,4,5,5-tetramethyl-2-(3-(triphenylen-3-yl)phenyl)-1,3,2-dioxaborolane
(4.0 g, 9.3 mmol), tetrakistriphenylphosphine palladium (0)
(Pd(PPh3)4) (0.21 g, 0.19 mmol), 40 mL of 2M potassium carbonate
(K.sub.2CO.sub.3) solution, and 160 mL of tetrahydrofurane (THF)
were put into a 250-mL round-bottom flask under an argon
atmosphere, and then refluxed and stirred. Thin-layer
chromatography (TLC) was applied to monitor the completion of the
reaction, and then an organic layer was isolated from the reaction
solution and vacuum-distilled, followed by column chromatography,
to obtain Compound M-4.
7) Synthesis of Compound N-5
##STR00112##
2,4-bis((1,1'-biphenyl)-4-yl)-6-chloro-1,3,5-triazine (6.2 g, 14.8
mmol),
4,4,5,5-tetramethyl-2-(3-(pyren-1-yl)phenyl)-1,3,2-dioxaborolane
(5.0 g, 12.4 mmol), tetrakistriphenylphosphine palladium (0)
(Pd(PPh3)4) (0.29 g, 0.25 mmol), 35 mL of 2M potassium carbonate
(K.sub.2CO.sub.3) solution, and 120 mL of tetrahydrofurane (THF)
were put into a 250-mL round-bottom flask under an argon
atmosphere, and then refluxed and stirred. Thin-layer
chromatography (TLC) was applied to monitor the completion of the
reaction, and then an organic layer was isolated from the reaction
solution and vacuum-distilled, followed by column chromatography,
to obtain Compound N-5.
8) Synthesis of Compound P-1
##STR00113##
2-chloro-4-(biphenyl-4-yl)-6-phenyl-1,3,5-triazine (3.2 g, 9.3
mmol),
4,4,5,5-tetramethyl-2-(3-(9,9'-spirobifluoren-2-yl)phenyl)-1,3,2-dioxabor-
olane) (4.0 g, 7.7 mmol), tetrakistriphenylphosphine palladium (0)
(Pd(PPh3)4) (0.18 g, 0.15 mmol), 25 mL of 2M potassium carbonate
(K.sub.2CO.sub.3) solution, and 100 mL of tetrahydrofurane (THF)
were put into a 250-mL round-bottom flask under an argon
atmosphere, and then refluxed and stirred. Thin-layer
chromatography (TLC) was applied to monitor the completion of the
reaction, and then an organic layer was isolated from the reaction
solution and vacuum-distilled, followed by column chromatography,
to obtain Compound P-1.
Hereinafter, embodiments for the manufacture of an organic light
emitting display device according to the present disclosure will be
disclosed. However, the following materials for the electron
transport layer do not limit the scope of the present
disclosure.
Embodiment 1
An organic light emitting display device is manufactured by
forming, on a substrate, an anode, a hole injection layer, a hole
transport layer, a blue light emitting layer, an electron transport
layer, an electron injection layer, and a cathode. Here, the
electron transport layer is formed of Compound B-3.
Embodiment 2
It has the same elements as the above-described Embodiment 1, and
the electron transport layer is formed of Compound C-2.
Embodiment 3
It has the same elements as the above-described Embodiment 1, and
the electron transport layer is formed of Compound G-3.
Embodiment 4
It has the same elements as the above-described Embodiment 1, and
the electron transport layer is formed of Compound G-6.
Embodiment 5
It has the same elements as the above-described Embodiment 1, and
the electron transport layer is formed of Compound L-1.
Embodiment 6
It has the same elements as the above-described Embodiment 1, and
the electron transport layer is formed of Compound M-4.
Embodiment 7
It has the same elements as the above-described Embodiment 1, and
the electron transport layer is formed of Compound N-5.
Embodiment 8
It has the same elements as the above-described Embodiment 1, and
the electron transport layer is formed of Compound P-1.
Comparative Example 1
It has the same elements as the above-described Embodiment 1, and
the electron transport layer is formed of the following anthracene
compound referred to as ETM1.
##STR00114##
Comparative Example 2
It has the same elements as the above-described Embodiment 1, and
the electron transport layer is formed of the following triazine
compound referred to as ETM2.
##STR00115##
The operating voltage, quantum efficiency, and lifetime of the
devices manufactured according to the above-described Embodiments 1
to 8 and Comparative Examples 1 and 2 were measured and shown in
the following Table 1. (The devices operated at a current density
of 10 mA/cm.sup.2 to measure the operating voltage, quantum
efficiency, and lifetime. T90 is the time it takes for the
luminance to decrease to 90% of the initial luminance. The
measurements taken in Embodiments and Comparative Example 2 were
expressed as a percentage relative to those taken in Comparative
Example 1 corresponding to 100%).
TABLE-US-00001 TABLE 1 External Operative quantum Lifetime voltage
efficiency (T90) Embodiment 1 90 137 139 Embodiment 2 91 125 180
Embodiment 3 95 128 253 Embodiment 4 93 127 236 Embodiment 5 95 120
207 Embodiment 6 88 135 174 Embodiment 7 96 111 129 Embodiment 8 94
126 215 Comparative 100 100 100 Example 1 Comparative 97 103 112
Example 2
Referring to Table 1, Embodiment 1 comprising Compound B-3 of this
disclosure showed a 10% decrease in operating voltage, a 37%
increase in external quantum efficiency, and a 39% increase in
lifetime, compared to Comparative Example 1 in which an anthracene
compound was used as an electron transport layer. Embodiment 2
comprising Compound C-2 of this disclosure showed a 9% decrease in
operating voltage, a 25% increase in external quantum efficiency,
and an 80% increase in lifetime, compared to Comparative Example 1.
Embodiment 3 comprising Compound G-3 of this disclosure showed a 5%
decrease in operating voltage, a 28% increase in external quantum
efficiency, and a 153% increase in lifetime, compared to
Comparative Example 1. Embodiment 4 comprising Compound G-6 of this
disclosure showed a 7% decrease in operating voltage, a 27%
increase in external quantum efficiency, and a 136% increase in
lifetime, compared to Comparative Example 1. Embodiment 5
comprising Compound L-1 of this disclosure showed a 5% decrease in
operating voltage, a 20% increase in external quantum efficiency,
and a 107% increase in lifetime, compared to Comparative Example 1.
Embodiment 6 comprising Compound M-4 of this disclosure showed a
12% decrease in operating voltage, a 35% increase in external
quantum efficiency, and a 74% increase in lifetime, compared to
Comparative Example 1. Embodiment 7 comprising Compound N-5 of this
disclosure showed a 4% decrease in operating voltage, an 11%
increase in external quantum efficiency, and a 29% increase in
lifetime, compared to Comparative Example 1. Embodiment 8
comprising Compound P-1 of this disclosure showed a 6% decrease in
operating voltage, a 26% increase in external quantum efficiency,
and a 125% increase in lifetime, compared to Comparative Example
1.
Also, Embodiment 1 comprising Compound B-3 of this disclosure
showed a 7% decrease in operating voltage, a 34% increase in
external quantum efficiency, and a 27% increase in lifetime,
compared to Comparative Example 2 in which a triazine compound
different from the compounds of this disclosure was used as an
electron transport layer. Embodiment 2 comprising Compound C-2 of
this disclosure showed a 6% decrease in operating voltage, a 22%
increase in external quantum efficiency, and a 68% increase in
lifetime, compared to Comparative Example 2. Embodiment 3
comprising Compound G-3 of this disclosure showed a 2% decrease in
operating voltage, a 25% increase in external quantum efficiency,
and a 141% increase in lifetime, compared to Comparative Example 2.
Embodiment 4 comprising Compound G-6 of this disclosure showed a 4%
decrease in operating voltage, a 24% increase in external quantum
efficiency, and a 124% increase in lifetime, compared to
Comparative Example 2. Embodiment 5 comprising Compound L-1 of this
disclosure showed a 2% decrease in operating voltage, a 17%
increase in external quantum efficiency, and a 95% increase in
lifetime, compared to Comparative Example 2. Embodiment 6
comprising Compound M-4 of this disclosure showed a 9% decrease in
operating voltage, a 32% increase in external quantum efficiency,
and a 62% increase in lifetime, compared to Comparative Example 2.
Embodiment 7 comprising Compound N-5 of this disclosure showed a 1%
decrease in operating voltage, a 8% increase in external quantum
efficiency, and a 17% increase in lifetime, compared to Comparative
Example 2. Embodiment 8 comprising Compound P-1 of this disclosure
showed a 3% decrease in operating voltage, a 23% increase in
external quantum efficiency, and a 103% increase in lifetime,
compared to Comparative Example 2.
From these results, it can be found out that the organic light
emitting display devices according to the embodiments using an
electron transport layer comprising a compound of this disclosure
reduced the operating voltage and improved the external quantum
efficiency and lifetime, compared to the organic light emitting
display device according to Comparative Example 1 using an
anthracene compound as an electron transport layer. Also, it can be
found out that the organic light emitting display devices according
to the embodiments using an electron transport layer comprising a
compound of this disclosure reduced the operating voltage and
improved the external quantum efficiency and lifetime, compared to
the organic light emitting display device according to Comparative
Example 2 using a triazine compound different from the compounds of
this disclosure as an electron transport layer.
As stated above, an organic compound of this disclosure comprises
p-biphenyl triazine as a core to facilitate electron movement
between neighboring p-biphenyl triazine groups within the molecular
stack of the electron transport layer. Moreover, an organic
compound of this disclosure includes an aryl group of at least 10
or more carbon atoms with high steric effect, which is a
substituent, and has an asymmetrical substitution form around a
triazine, in order to have an amorphous structure by eliminating
coplanarity and reducing symmetry. Accordingly, the electron
transport layer is formed of an organic compound of this disclosure
to improve electron mobility, thereby reducing the operating
voltage of the device and improving the efficiency.
Although embodiments have been described with reference to a number
of illustrative embodiments thereof, it should be understood that
numerous other modifications and embodiments can be devised by
those skilled in the art that will fall within the scope of the
principles of this disclosure. More particularly, various
variations and modifications are possible in the component parts
and/or arrangements of the subject combination arrangement within
the scope of the disclosure, the drawings and the appended claims.
In addition to variations and modifications in the component parts
and/or arrangements, alternative uses will also be apparent to
those skilled in the art.
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